Nassco, a wholly-owned subsidiary of General Dynamics, has begun building the fifth vessel in a series of product carriers for US Shipping Partners.

The double-hulled Evergreen State will measure 183m in length with a cargo capacity of around 331,000 barrels.

The vessel will carry petroleum and chemical products in Jones Act trade between US ports.

The ship will be delivered in the third quarter of 2010.

NASSCO is a major shipbuilding and repair yard, located on the West Coast of the US.